Editing X-ray astronomy (section)

==Analytical X-ray astronomy==
[[High-mass X-ray binaries]] (HMXBs) are composed of OB supergiant companion stars and compact objects, usually [[neutron stars]] (NS) or [[black holes]] (BH). Supergiant X-ray binaries (SGXBs) are HMXBs in which the compact objects orbit massive companions with orbital periods of a few days (3–15 d), and in circular (or slightly eccentric) orbits. SGXBs show typical the hard X-ray spectra of accreting [[pulsar]]s and most show strong absorption as obscured HMXBs. X-ray luminosity (''L''<sub>x</sub>) increases up to 10<sup>36</sup> erg·s<sup>−1</sup> (10<sup>29</sup> watts).{{citation needed|date=July 2019}}

The mechanism triggering the different temporal behavior observed between the classical SGXBs and the recently discovered [[X-ray transient#Supergiant Fast X-ray Transients (SFXTs)|supergiant fast X-ray transients]] (SFXT)s is still debated.<ref name=ZuritaHeras>{{Cite journal|author=Zurita Heras JA|author2= Chaty S |title=Discovery of an eccentric 30 day period in the supergiant X-ray binary SAX J1818.6–1703 with INTEGRAL |journal=Astronomy and Astrophysics|date=2009 |volume=493|issue=1 |page=L1|doi=10.1051/0004-6361:200811179 |bibcode=2009A&A...493L...1Z|arxiv = 0811.2941 |s2cid= 17863072 }}</ref>
{{anchor|Stellar X-ray astronomy}}